The Interaction Among Mesoscale Dynamics, Microphysical Properties and Radiative Effects of Mid-latitude Cirrus Clouds

卷云是在多种动力和热力条件下形成的，对地球的辐射能量平衡有着深远的影响。卷云的辐射特性和辐射影响本质上受其微物理和宏观物理特性的控制。然而，控制卷云形成、微物理演化和生命周期以及影响其中尺度变率的物理和动力机制还不是很清楚，这反过来又阻碍了对各种条件下卷云辐射影响的可靠量化。本研究的主要目标是显著提高我们对中纬度卷云的微物理和宏观物理特性与它们形成的气团的动力和热力学特性之间联系的理解。我们试图对大尺度和中尺度动力强迫、卷云的微物理和宏观物理特性及其辐射特性之间的联系提供详细的、基于过程的理解。本研究使用的方法将(1)数值模拟与云分辨区域模式相结合；(2)基于大尺度和中尺度动力强迫的卷云事件动态分类技术；(3)模拟卷云特性与飞机和遥感观测的比较。云分辨区域模式模拟允许对卷云的微物理和宏观物理特性进行详细和基于过程的研究，并对影响卷云演化和生命周期的物理和动力机制以及由卷云存在引起的中尺度动力反馈提供更深入的了解。大气状态分类技术使我们能够统计地将大气动力状态与卷云的微物理和宏观物理特征联系起来，使我们能够得出基于物理和统计的结论，了解不同的大尺度和中尺度动力强迫如何影响卷云的性质。分类结果对于评价和改进基于状态依赖方法的卷云微物理参数化至关重要。模式模拟与观测的比较利用了前所未有的中纬度卷云新微物理观测数据集。对卷云的微观物理和动力学控制的理解将大大提高，并更好地理解这些控制如何影响中纬度卷云的宏观物理和辐射特性。这些知识对于改进微物理参数化将是无价的，并导致在各种尺度的数值模型中更基于物理的卷云微物理、宏观物理和辐射特性的表示。改进后的卷云特性表示将有助于更好地量化中纬度卷云的辐射影响。本工作计划开展研究生教育和培训，与其他科学家合作，改进微物理参数化和卷云在云分辨区域模式中的表示，以及参与国际模式的相互比较。新获得的数据集和结果将被存档并与更广泛的研究界共享。我们的研究成果将被记录在同行评审的出版物中，并通过我们在国内和国际研讨会和会议上的参与和演讲来传播。此外，我们将让代表性不足的少数民族学生参与我们的研究，并在本科生和高中生的课程开发中使用数据分析的元素。

Cirrus clouds form under a variety of dynamical and thermodynamical conditions, and have a profound impact on the radiative energy balance of the Earth. The radiative properties and the radiative impact of cirrus clouds are inherently controlled by their microphysical and macrophysical properties. However, the physical and dynamical mechanisms that govern the formation, microphysical evolution, and the life cycle of cirrus clouds and influence their mesoscale variability are not very well understood, which in turn hinders confident quantification of the radiative impact of cirrus under various conditions. The primary goal of this research is to significantly improve our understanding of the linkages between the microphysical and macrophysical properties of mid-latitude cirrus clouds and the dynamical and thermodynamical properties of the air masses in which they form. We seek to provide a detailed and process-based understanding of the links between the large scale and mesoscale dynamical forcing, the microphysical and macrophysical properties of cirrus clouds and their radiative properties. The methodology used in this study combines (1) numerical simulations with a cloud-resolving regional model; with (2) a novel dynamical state classification technique to cluster cirrus cloud events according to large scale and mesoscale dynamical forcing; and (3) comparison of simulated cirrus cloud properties with observations from aircraft and remote sensors.The cloud-resolving regional model simulations allow for a detailed and process-based investigation of the microphysical and macrophysical properties of cirrus clouds, as well as provide deeper insight into the physical and dynamical mechanisms that affect the evolution and life cycle of cirrus and the mesoscale dynamical feedbacks that are caused by the presence of cirrus. The atmospheric state classification technique enables us to statistically link atmospheric dynamical states with the microphysical and macrophysical characteristics of cirrus clouds, allowing us to draw physically and statistically based conclusions regarding how cirrus cloud properties are affected by different large scale and mesoscale dynamical forcings. The results of the classification are crucial for evaluating and improving cirrus microphysical parameterizations in a regime dependent approach. Comparison of model simulations with observations makes use of an unprecedented data set of new microphysical observations in mid-latitude cirrus clouds.Intellectual merit Substantially improved understanding of the microphysical and dynamical controls of cirrus clouds and a better understanding of how these controls affect the macrophysical and radiative properties of mid-latitude cirrus will be obtained. This knowledge will be invaluable for improving microphysical parameterizations and lead to a more physically based representation of cirrus microphysical, macrophysical, and radiative properties in numerical models on various scales. The improved representation of cirrus cloud properties will then help to better quantify the radiative impact of mid-latitude cirrus.Broader impacts Graduate education and training, collaboration with other scientists, improvement of microphysical parameterization and representation of cirrus clouds in cloud-resolving regional models, and participation in international model inter-comparisons are all planned in this work. Newly acquired data sets and results will be archived and shared with the broader research community. Our research results will be documented in peer-reviewed publications and disseminated through our participation in and presentations at national and international workshops and conferences. In addition we will engage underrepresented minority students in our research and use elements of the data analysis in curriculum development for undergraduate and high school students.